Inlet manifold



Nov. 11, 1930. H. BROWNBACK INLET MANIFOLD Filed July 17, 1928 INVENTOR. *Hiww Lam W Patented Nov. 11, 1930 A NT OFFICE ;HENRY LOWE BROWNBACK, OF NORRISTOWN, PENNSYLVANIA ,INIQET MANIFOLD ,lA pp lication filed July 17,

This inventionis an improvement in inlet manifolds particularly designed for multiple cylinder internal combustion engines having the cylindersarranged radially about the crankshaft, and the principal object of the 'inventionis' to provide a simple, novel and efficient annular inlet manifold which will distribute the fuel vapors or gases evenly to all the cylinders; and furthermore will pro- 1U vide the same volume of fuel vapors or gases at the same'velocity to each cylinder, the vapors or gases travelilig through the same length of passage through the manifold and 'ntake pipes from the carburetor to each cyl- Thejdiihculty of providing an evenly distributed mixture 1 of fuel vapors to this type of internal combustion engine with the cylinders arranged radially about the axis of the crankshaft, has long been recognized, and the'conditions which exist have been accepted as inevitable although attempts have been madeto obviate this difficulty by the use-of more'or less complicated means such as providing' separate manifolds feeding a certain number of cylinders, the usual number of separate manifolds used on a nine cylinder engine being three also rotary elements or the like in the manifolds have been used in the manifold to counteract'this difficulty.

'I will explain the invention withreference to the accompanyingdrawingwhich illustrates one practical embodiment thereof to enable otherslfamiliar with the art to adopt and use the same; and will summarize in the claims the novelfeatures of construction, and novel combinations of parts, for which protection isjdesired.

,In said drawings 1- Figure 1 .is an elevation showing diagrammatically ath-cylinder radial type. internal combustion engine to which my novel inlet manifold is applied. 1 r

FigureEZ is an enlargedtransverse sectionthrough one of the cylinders and inlet manifoldt i i i a Figure 3 is a section through an ordinary inlet manifold fora 5 cylinder radial engine.

50 Figure 4 is a similar section through my 1928. SerialN'o. 293,454.

inder radial engine.

As shownin Figs. 1 and 2, the invention is illustrated in connection with a 5-cylinder radial type internal combustion engine, the five cylinders being indicatedby the letters A, B, C, D, and E, and the cylindersbeing all evenly spaced around the crankshaft F. G (Fig.2) represents the inletva-lve, and H the outlet valve, the valve being actuated by rocker arms K and push rods L. The intake pipes for each cylinder are indicated by the letter M. i

Formed integrally with or attached to one end of the crank case N, co axial with the 65 crank shaft F, is an annular inletmanifol'cl 1 (Fig. 2) having 5 evenly spaced outlets 1 opposite each of the cylinders A to E inclusive; which outlets are connected respectively with pipes M leadingto the respective inlet valve G of the cylindersas shown 'inFig. 2. The pipes M for all the cylinders A,"B, C, D and E are similarly connectedto thei-r respective inlet ports as shown in 2 and all the pipes M are of the same length. At the bottom of the annular inlet manifold 1, preferably disposed mi dwa fibetween the outlets 1 for cylinders A and E is'a carburetor header 1 for attachment thereto of a carburetor P for supplying fuel vapors to each of the cylinders. 1

Referring to Fig. 3 which shows the usual annular inlet manifold, detached, the fuel vapors from carburetor P enter theannular manifoldlthrough header 1 and divide as shown by the arrows, passing upwardlyat each side of the manifold towards the upper outlet 1 for cylinder G. In this construction obviously there can be no even distribution of the fuelvapor or gasmjxture primarily, for the reason that the distances from header 1 to outlets 1;"- for the different cylinders A and E is shorter than the distance to cylinders B and D; and cylinder Cwould receive the g5 lightest vapors which must travel the longest path, and the solution of the ditficulty in obtaining an evenly distributed fuel lnixture lies in providing the same volume of gas to each cylinder at the same velocity and passing novel inlet manifold designed fora 5 cylthrough the same lengthof passage in the manifold 1 from the carburetor P.

Even if two inlet-s were provided from carburetor P, one entering the manifold l midway between cylinders A and B andthe other inlet 1 entering manifold 1 midway between cylinders D and E,.the.results would be worse asthe heavyingredients of the fuel mixture would"puddle at the bottom of the manifold l and thereby give cylinders A and E an over-rich mixture; furthermore the dis tances to each cylinder would vary enormouslv also.

My solution to the problem is clearly illustrated in Fig. 4, in which the manifold 1 is formed as 'two con centric annular rings by provid ng an annular. wall 1 ;w 1th1n the manifold, equally. dividing thecross-sect ional to itsrespective cylinder,

area of the'manifold linto two separate annular compartments or ducts 'Rfand S. The header l is likewise divided by a wall 1 one side of the wall 1? in header 1 communicating only with theinner duct S, and the other side of 1 communicating with only the outer duct R. In the, annular wall 1 opposite each of the outlet ports 1 is an open ing 1 whereby the fuel gas from the inner duct S may pass directly through the outer duct R and intothe outlet port 1 and hence.

Header 1- 4 is also disposed atthe lower end ofthe manifold 1, and header 1 may be connected-gin any well known mannereitherto a single carburetor P, or to a caror to two separate carburetors the same form I ing no part of the present invention. The

fuelgasesfrom the carburetor P divide-.at the wall 1 and pass upwardlythrough their respective ducts" R and S towards the end f of the said ducts, the gases in duct S traveling in the opposite direction from those in duct R asindicated by the arrows in Fig. 4;. A fillet l at the end of duct S directs the fuel gases out through hole l i'nto cylinder E and closes the end of-said duct S. Similarly a fillet 1 closes the outer duct R directing the gases therefrom through hole 1 into cylinder A. V I

By reason of'the' holes 1 in annularwall 1?, andthe opposite directions of travel of each half of thefuel gases in ducts R and S the total distance traveled by the total fuel vapors for'each cylinder fromthe carburetor P is the'same for each cylinder, since half the fuel gases must travel in one direction which may be a short route through duct R as in the case of cylinder E and the other'half for cylinder-E must travel in the opposite direction by way of thelong route through duct S. -VVith the engine shown in Fig. 1 the five cylinder radial. motor rising might have two firing orders, viz,AC-E.BD; or

I do not limit my invention to the exact buretor having a double mixing chamber,v

form shown in the drawing for obviously changes may be made therein within the scope of the claims; and moreover my novel manifold may housed on anymultiple cylinderradial type engine.

1.111 a multiple cylinder internal combustion; engine, an intake manifold having a plurality of fuel ducts extending from the carburetor to the inlet of each cylinder whereby eachicylinderv is supplied with a like volume of fuel vapors at any engine speed.-

4 2. In an engine as set forth in claim 1, said manifold having adjacent ducts each receiving-half of the'fuel vapors and conducting same in oppositedirections, In a' multiple cylinder internal combustion engine,.an'intakemanifold having a plu rality of ducts each extending from the carbureter' tothe inlet of each cylinder and whereby each cylinder is supplied with alike same velocity and through approximately the same length of ducts at anyengine speed. 4:. In anengin-e as set forth in claim 3,- said 7 manifold being circular and having two ad:

jacent ducts each receiving half the fuel a vapors and conducting. same inopposite dir-ections.- in j 5. In a multiple cylinder internal combus tion engine an intake manifold having ducts extending from the carburetertothe inlet of .eaclpcylinder, adaptedto feed tojeach cylinder the same volume of fuelvapors at the same velocity through the 'sameilength of 'volumeof fuel vapors at approximately the a manifold ducts at any'engine speed; and I having ducts feeding to each cylinder the same volume of fuel vapors at the same veloc ducts 'atjany engine speed; and 'gmeans fo feding fuel vapors to the'manifold. 1

8. In an engine as set forth'in'claim 7-,"said manifold being annular and having two ad ity through the same length of "manifold .j'acent ductseach'receiving halfthe fuel vapors and conducting same in opposite directions around the'manifold. I v

9. An intake manifold for'im'ultiple cylin- -der internal combustion engines comprisln'g a circular body having two adjacent ducts adapted to conduct fuel vapors in opposite directions; vmeans for introducing half the fuel vapors into each duct and an inlet port --for each cylinder tappingboth ducts.

10. An intake manifold for radial type multiple cylinder internal combustion engines comprising an annular body having two adjacent ducts adaptedto conduct fuel vapors in opposite directions; means for introducing half the fuelvapors into each duct at the same point; and an inlet port for each cylinder tapping both ducts.

11. An intake manifold for multiple cylinder internal combustion engines, comprising an annular body having a carburetor header; a partition in the header for dividing the fuel gases; an annular division wall in the annular body dividing same into two adjacent ducts, one duct communicating with the header at one side of the partition and the other duct communicating with the header at the other side of the partition; and an inlet port for each cylinder communicating with both ducts.

12. An intake manifold for multiple cylinder internal combustion engines, comprising an annular body having a carburetorheader; a partition wall in the header for dividing the fuel gases; an annular division wall in the manifold dividing same into adjacent inner and outer ducts, one duct communicating with the header at one side of the partition and the other duct communicating with the header at the other side of the partition; and an inlet port for each cylinder communicating directly with the outer duct and also with theinner duct through an opening in the annular division wall opposite such inlet port.

HENRY LOWE BROWNBACK. 

